<template>
    <!--ref 可以获得到页面元素-->
    <div class="list" ref="wrapper">
        <div >
          <div class="area">
            <div class="title border-topbottom">当前城市</div>
            <div class="button-list">
              <div class="button-wrapper">
                <div class="button">{{this.currentCity}}</div>
              </div>
            </div>
          </div>

          <div class="area">
            <div class="title border-topbottom">热门城市</div>
            <div class="button-list">
              <div class="button-wrapper" v-for="item in hot" :key="item.id" @click="handleCityClick(item.name)">
                <div class="button">{{item.name}}</div>
              </div>

            </div>
          </div>

          <!--注意，这里循环的是对象-->
          <div class="area" v-for="(item, key) in cities" :key="key" :ref="key" >
            <div class="title border-topbottom">{{key}}</div>
            <div class="item-list">
              <div class="item border-bottom" v-for="innerItem of item" :key="innerItem.id" @click="handleCityClick(innerItem.name)" >
                {{innerItem.name}}
              </div>
            </div>
          </div>
        </div>
    </div>
</template>

<script>

  // 引入滑动组件
  import Bscroll from 'better-scroll'
  import {mapState, mapMutations} from 'vuex'

  export default {
    name: 'CityList',
    //页面加载之后，挂载这个组件
    mounted () {
      this.scroll = new Bscroll(this.$refs.wrapper)
    },
    props: {
      hot: Array,
      cities: Object,
      letter: String,
    },
    computed: {
      ...mapState({
        //将vux中的city映射到 当前的计算属性currentCity 中
        currentCity: 'city'
      })
    },
    methods: {
      handleCityClick(city){
        // this.$store.commit('changeCityData', city);
        this.changeCityData(city);
        //路由跳回首页
        this.$router.push('/')
      },
      ...mapMutations(['changeCityData'])
    },
    watch: {
      //监听器
      letter() {
        if (this.letter != null){
          const elment = this.$refs[this.letter];
          //跳到这个元素上去，不能少了:ref="key"
          this.scroll.scrollToElement(elment[0]);
        }
      }
    }
  }
</script>

<style scoped lang="stylus">

  @import "~styles/varibles.styl"

  .border-topbottom
    &:before
      border-color: #ccc
    &:after
      border-color: #ccc
  .border-bottom
    &:before
      border-color: #ccc
  .list
    overflow: hidden
    position: absolute
    top: 1.58rem
    left: 0
    right: 0
    bottom: 0
    .title
      line-height: .54rem
      background: #eee
      padding-left: .2rem
      color: #666
      font-size: .26rem
    .button-list
      padding: .1rem .6rem .1rem .2rem
      overflow: hidden
      .button-wrapper
        float: left
        width: 33.3%
      .button
        margin: .1rem
        padding: .1rem 0
        border-radius: .06rem
        text-align: center
        border: .02rem solid #ccc
    .item-list
      .item
        line-height: .54rem
        color: #666
        padding-left: .2rem
</style>
